MLA

Saarinen, Eero, 1910-1961. Models. Box 230, folder 756. undated. https://collections.library.yale.edu/catalog/10016953.

APA, 6th edition

Saarinen, Eero, 1910-1961. (["Box 230, folder 756"])(undated)[Models]. https://collections.library.yale.edu/catalog/10016953.